Pentanuclear iron catalysts for water oxidation: substituents provide two routes to control onset potentials

• DOI: 10.1039/c9sc00678h
• Publication Date: 2019-03-19T19:05:14Z
• Authors: Vijayendran K. K....; Mio Kondo; Masaya Okamura; Takuya Akai; Hitoshi Izu; Shigeyuki Masaoka
• Keywords: Chemistry; 540; 01 natural sciences; 0104 chemical sciences

The development of robust and efficient molecular catalysts based on earth-abundant transition metals for water oxidation reactions is a challenging research target. Our group recently demonstrated the high activity stability pentairon-based electrocatalyst (M. Okamura, M. Kondo, R. Kuga, Y. Kurashige, T. Yanai, S. Hayami, V. K. Praneeth, Yoshida, Yoneda, Kawata Masaoka, Nature, 2016, 530, 465-468). However, strategies to decrease onset potentials catalysis remains challenging. In this article, we report construction series pentanuclear iron complexes by introducing electron-donating (methyl) electron-withdrawing (bromo) substituents ligand. Two newly synthesized exhibited five reversible redox processes, similar what seen with parent complex. These can also serve as homogeneous reactions, faradaic efficiencies were high. Additionally, developed lower than that Mechanistic insights revealed there are two methods decreasing potentials: control pentairon complex reaction mechanism.